To the rescue comes Takeshi Mizumoto at Kyoto University in Japan. He showed a conference on applied intelligent systems in Dalian, China, this week a theremin able to cope with such incursions - as you can see in the video above. "The robot plays the correct pitch even if a guitarist comes closer to the theremin in a jam session," he says. His trick is an adaptive pitch-control algorithm that tracks the tune the robot plays and attempts to stop the pitch diverging when the human interrupts it.

Luckily, it's not just useful for keeping theremin-playing robots in tune. He says the algorithm, which currently reduces unmelodious errors by 90 per cent, will have practical uses when refined further - in allowing robots to track human faces in video footage.